183732

Appears in sequences

• Number of associative binary operations on an n-set; number of labeled semigroups.at n=5A023814
• Number of 2n-bead balanced binary necklaces which are equivalent to their reverse, but not equivalent to their complement and reversed complement.at n=21A045676
• Triangle read by rows: T(n,k) (1 <= k <= n) = number of ascendingly generated semigroups of order n with k generators.at n=14A256411